Thanks to all who replied!
Yes I have another DVM: a Fluke 179... and yes I know this is an overkill for a hobbyist...
But I love well made products...
This Fluke 75 meter, as I said, was a unreachable dream decades ago...
Even if I cannot revive it, I still am glad to own it now... Silly maybe?!
I can understand that putting time into this for members of this great forum is a waste of time but I do appreciate any help!
To answer the question of @lowimpedance:
@OP, when you say section 3.21 failed do you mean you measured 0.2 mV at Z1 pin 3 or further along at the filter ?.
One other quick check to make sure the crystal y1 is oscillating.
However if your sure U1 is dead then as suggested your only bet would be a junker unit , keep an eye out on your favourite 'auction site' or perhaps put a WTB request in the BUY/SELL/WANTED board and hopefully one will turn up.
- I will certainly look for another unit for spare parts... I saw a Fluke 23 in working order for 57 euro's... But a broken unit will be cheaper hopefully
- the DVM has problems coming out of the display selftest now, after 3 minutes it passes that 'test'...
- The VAC and VDC modes give a overrange 'OL' continually
- The oscillator is working! I measured it: 32.76Khz but the voltage pp was 2.2V instead of the 600mV stated?
- pin 1 of the input divider Z1 is 2V DC as it should be so no shorted MOV or open R1
- pin 3 of Z1 should be 200Mv but is basically zero! Yesterday I said I measured 0.2mV but in the Fluke 179 mV range that is just noise
I will investigate the divider, solder it out and check it.
after that I think removing the S1 rotary switch and checking it will be useful.
again, thanks to everyone willing to think with me to restore this beautiful DVM.